chore: revert back to using ref when triggering e2e-tests workflow

Author: dphang

.github/workflows/CI.yml

@@ -58,4 +58,7 @@ jobs:
         with:
           workflow: End-to-end Tests
           token: ${{ secrets.BOT_GITHUB_TOKEN }}
-          ref: ${{ github.event.pull_request.head.sha || github.sha }}
+          ref: ${{ github.event.pull_request.head.ref || github.ref }}
+          # FIXME: Passing sha doesn't seem to work, created GitHub ticket here: https://i.8713187.xyzmunity/t/workflow-dispatch-cant-set-ref-to-commit-sha/138132
+          # But using ref (branch name) should be fine as it means tests always run on latest commit on PR or master branch
+          # ref: ${{ github.event.pull_request.head.sha || github.sha }}